Norm Ferns Prakash Panangaden Doina Precup Metrics for Markov Decision Processes with Infinite State Spaces. 201-208 2005 conf/uai/2005 UAI http://uai.sis.pitt.edu/displayArticleDetails.jsp?mmnu=1&smnu=2&article_id=1175&proceeding_id=21 db/conf/uai/uai2005.html#FernsPP05